Sole structure for article of footwear

ABSTRACT

A kit includes a first article of footwear and a second article of footwear. The first article of footwear includes a first upper, a first sole structure having a first outsole defining a first ground-contacting surface, and a first side support extending between and connecting the first upper and the first outsole at a medial side of the first article of footwear. The second article of footwear including a second upper, a second sole structure having a second outsole defining a second ground-contacting surface, and a second side support extending between and connecting the second upper and the second outsole at a lateral side of the second article of footwear. In one aspect, the first sole structure includes a first fluid-filled chamber and the second sole structure includes a second fluid-filled chamber, wherein the first fluid-filled chamber is identical to the second fluid-filled chamber.

CROSS REFERENCE TO RELATED APPLICATION

This non-provisional U.S. Patent application claims priority under 35 U. S. C. § 119(e) to U.S. Provisional patent application Ser. No. 63/291,153, filed Dec. 17, 2021, the disclosure of which is hereby incorporated by reference in its entirety.

FIELD

The present disclosure relates generally to sole structures for articles of footwear and, more particularly, to sole structures incorporating an outsole.

BACKGROUND

This section provides background information related to the present disclosure, which is not necessarily prior art.

Articles of footwear conventionally include an upper and a sole structure. The upper may be formed from any suitable material(s) to receive, secure, and support a foot on the sole structure. The upper may cooperate with laces, straps, or other fasteners to adjust the fit of the upper around the foot. A bottom portion of the upper, proximate to a bottom surface of the foot, attaches to the sole structure.

Sole structures generally include a layered arrangement extending between a ground surface and the upper. One layer of the sole structure includes an outsole that provides abrasion-resistance and traction with the ground surface. The outsole may be formed from rubber or other materials that impart durability and wear-resistance, as well as enhance traction with the ground surface. Another layer of the sole structure includes a midsole disposed between the outsole and the upper. The midsole provides cushioning for the foot and may be partially formed from a polymer foam material that compresses resiliently under an applied load to cushion the foot by attenuating ground-reaction forces. The midsole may additionally or alternatively incorporate a cushion member to increase the durability of the sole structure, as well as to provide cushioning to the foot by compressing resiliently under an applied load to attenuate ground-reaction forces. The cushion member may be a fluid-filled bladder or a foam element. Sole structures may also include a comfort-enhancing insole or a sockliner located within a void proximate to the bottom portion of the upper and a strobel attached to the upper and disposed between the midsole and the insole or sockliner.

Midsoles employing fluid-filled bladders typically include a bladder formed from two barrier layers of polymer material that are sealed or bonded together. The fluid-filled bladders are pressurized with a fluid such as air, and may incorporate tensile members within the bladder to retain the shape of the bladder when compressed resiliently under applied loads, such as during athletic movements. Generally, bladders are designed with an emphasis on balancing support for the foot and cushioning characteristics that relate to responsiveness as the bladder resiliently compresses under an applied load. In such an aspect, the midsole may include a chassis for interfacing with the bladder so as to form a unitary structure.

Outsoles typically cover a bottom surface of the midsole and provide abrasion-resistance and traction with the ground surface. Such outsoles are typically formed as a single piece that is attached to the bottom surface of the midsole.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected configurations and are not intended to limit the scope of the present disclosure.

FIG. 1A is a perspective view of an article of footwear for a left foot including a sole structure in accordance with principles of the present disclosure;

FIG. 1B is a perspective view of an article of footwear for a right foot including a sole structure in accordance with principles of the present disclosure;

FIG. 2A is an exploded, top perspective view of the sole structure of FIG. 1A;

FIG. 2B is an exploded, top perspective view of the sole structure of FIG. 1B;

FIG. 3A is an exploded, bottom perspective view of the sole structure of FIG. 1A;

FIG. 3B is an exploded, bottom perspective view of the sole structure of FIG. 1B;

FIG. 4A is a top perspective view of a first aspect of a cushion for use in the sole structure of FIGS. 1A and 1B;

FIG. 4B is a bottom perspective view of the cushion of FIG. 4A;

FIG. 5A is a bottom plan view of the cushion of FIG. 4A;

FIG. 5B is a bottom plan view of another aspect of a cushion for use in the sole structure of FIGS. 1A and 1B;

FIG. 6A is a cross-sectional view of the cushion of FIG. 4A, taken along Line 6A-6A;

FIG. 6B is a cross-sectional view of another aspect of the cushion of FIG. 5B, taken along Line 6B-6B;

FIG. 7 is a cross-sectional view of the cushion of FIG. 5A, taken along Line 7-7;

FIG. 8 is a cross-sectional view of the cushion of FIG. 5A taken along Line 8-8;

FIG. 9 is a side view of a side support;

FIG. 10 is a perspective view of the interior of the side support;

FIG. 11 a top plan view of the sole structure of FIG. 1 ;

FIG. 12 is a cross-sectional view of the sole structure of FIG. 11 , taken along Line 12-12;

FIG. 13 is a cross-sectional view of the sole structure of FIG. 11 , taken along Line 13-13;

FIG. 14 is a cross-sectional view of the sole structure of FIG. 11 , taken along Line 14-14;

FIG. 15 is a cross-sectional view of the sole structure of FIG. 11 , taken along Line 15-15;

FIG. 16 is a cross-sectional view of the sole structure of FIG. 11 , taken along Line 16-16; and

FIG. 17 is a cross-sectional view of the sole structure of FIG. 11 , taken along Line 17-17.

Corresponding reference numerals indicate corresponding parts throughout the drawings.

DETAILED DESCRIPTION

Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure.

The terminology used herein is for the purpose of describing particular exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed.

When an element or layer is referred to as being “on,” “engaged to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, attached, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections. These elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example configurations.

One aspect of the disclosure provides a kit including a first article of footwear and a second article of footwear. The first article of footwear includes a first upper, a first sole structure having a first outsole defining a first ground-contacting surface, and a side support extending between and connecting the first upper and the first outsole at a medial side of the first article of footwear. The second article of footwear includes a second upper, a second sole structure having a second outsole defining a second ground-contacting surface, and a second side support extending between and connecting the second upper and the second outsole at a lateral side of the second article of footwear.

Implementations of the disclosure may include one or more of the following optional features. In some implementations, the first outsole is a first plate and the second outsole is a second plate.

In some configurations, the kit further includes a first fluid-filled chamber disposed between the first plate and the first upper and a second fluid-filled chamber disposed between the second plate and the second upper.

In some configurations, the first plate and the first side support include a higher rigidity than a material forming the first fluid-filled chamber and the second plate and the second side support include a higher rigidity than a material forming the second fluid-filled chamber.

In some configurations, the first side support is disposed in a forefoot region of the first sole structure and the second side support is disposed in a forefoot region of the second sole structure.

In some configurations, the first sole structure includes a first fluid-filled chamber disposed between the first outsole and the first upper and the second sole structure includes a second fluid-filled chamber disposed between the second outsole and the second upper.

In some configurations, at least one of the first fluid-filled chamber and the second fluid-filled chamber is pressurized and/or includes a tensile member disposed therein.

In some configurations, the first fluid-filled chamber extends continuously and uninterrupted from a forefoot region of the first sole structure to a heel region of the first sole structure along the medial side and the second fluid-filled chamber extends continuously and uninterrupted from a forefoot region of the second sole structure to a heel region of the second sole structure along the lateral side.

In some configurations, the first fluid-filled chamber includes at least one first weld extending from a lateral edge of the first fluid-filled chamber in a direction toward the medial side of the first sole structure and the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.

In some configurations, the first fluid-filled chamber and the second fluid-filled chamber are identical to one another.

Another aspect of the disclosure provides a kit including a first article of footwear and a second article of footwear. The first article of footwear includes (i) a first upper and (ii) a first sole structure having a first plate defining a first ground-contacting surface and a first fluid-filled chamber disposed between the first plate and the first upper, the first fluid-filled chamber extending continuously and uninterrupted from a forefoot region of the first sole structure to a heel region of the first sole structure along a medial side of the first sole structure. The second article of footwear includes (i) a second upper and (ii) a second sole structure having a second plate defining a second ground-contacting surface and a second fluid-filled chamber disposed between the second plate and the second upper, the second fluid-filled chamber extending continuously and uninterrupted from a forefoot region of the second sole structure to a heel region of the second sole structure along a lateral side of the second sole structure.

Implementations of the disclosure may include one or more of the following optional features. In some implementations, the first fluid-filled chamber includes at least one first weld extending from a lateral edge of the first fluid-filled chamber in a direction toward the medial side of the first sole structure.

In some configurations, the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.

In some configurations, the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.

In some configurations, at least one of the first fluid-filled chamber and the second fluid-filled chamber is pressurized and/or includes a tensile member disposed therein.

In some configurations, the first fluid-filled chamber and the second fluid-filled chamber are identical to one another.

In some configurations, a first side support extends between and connects the first upper and the first plate at a medial side of the first article of footwear and a second side support extends between and connects the second upper and the second plate at a lateral side of the second article of footwear.

In some configurations, the first plate and the first side support include a higher rigidity than a material forming the first fluid-filled chamber and the second plate and the second side support include a higher rigidity than a material forming the second fluid-filled chamber.

In some configurations, the first side support is disposed in a forefoot region of the first sole structure and the second side support is disposed in a forefoot region of the second sole structure.

In some configurations, the first side support is identical to the second side support.

In some configurations, the first side support and the second side support includes a plurality of gaps spaced apart from each other to define a plurality of slats.

Referring to FIGS. 1A-16 , a kit 400 includes a first article of footwear 10A (shown in FIG. 1A) and a second article of footwear 10B (shown in FIG. 1B). Each of the first and second articles of footwear 10A, 10B includes a sole structure 100A, 100B and an upper 300A, 300B attached to the sole structure 100A, 100B. The article of footwear 10A, 10B may be divided into one or more regions as shown in FIG. 11 . The regions may include a forefoot region 12, a mid-foot region 14, and a heel region 16. The forefoot region 12 may be further described as including a toe portion 12T corresponding to the phalanges of the foot, and a ball portion 12B corresponding to a metatarsophalangeal (MTP) joint. The mid-foot region 14 may correspond with an arch area of the foot, and the heel region 16 may correspond with rear portions of the foot, including a calcaneus bone. The footwear 10A, 10B may further include an anterior end 18 associated with a forward-most point of the forefoot region 12, and a posterior end 20 corresponding to a rearward-most point of the heel region 16. A longitudinal axis A₁₀ of the footwear 10A, 10B extends along a length of the footwear 10 from the anterior end 18 to the posterior end 20, and generally divides the footwear 10A, 10B into a medial side 22 and a lateral side 24, as shown in FIG. 11 , wherein the medial side 22 refers to the interior side of each of the articles of footwear 10A, 10B when worn and the lateral side refers to the exterior side of each of the articles of footwear 10A, 10B when worn. Accordingly, the medial side 22 and the lateral side 24 respectively correspond with opposite sides of the footwear 10 and extend through the regions 12, 14, 16.

FIG. 1A is a perspective view taken from the medial side 22 of the first article of footwear 10A, which is configured to be worn on the left foot. FIG. 1B is a perspective view taken from the lateral side 24 of the second article of footwear 10B, which is configured to be worn on the right foot. When worn together, the first article of footwear 10A and the second article of footwear 10B define the kit 400, which in this particular disclosure is suited for running on a track in a counter-clockwise direction. The construct of the first and second article of footwear 10A, 10B is designed to provide cushion and stability to the medial side 22 of the left foot and the lateral side 24 of the right foot when rounding the turns of a track in a counter-clockwise direction, as will be explained in greater detail below.

The article of footwear 10A, 10B and, more particularly, the sole structure 100A, 100B, may be further described as including an interior region 26 and a peripheral region 28, as indicated in FIGS. 1A, 1B. The peripheral region 28 is generally described as being a region between the interior region 26 and an outer perimeter of the sole structure 100A, 100B. Particularly, the peripheral region 28 extends from the forefoot region 12 to the heel region 16 along each of the medial side 22 and the lateral side 24, and wraps around each of the forefoot region 12 and the heel region 16. Thus, the interior region 26 is circumscribed by the peripheral region 28, and extends from the forefoot region 12 to the heel region 16 along a central portion of the sole structure 100A, 100B.

With reference to FIGS. 2A-3B, a perspective view of the sole structure 100A, 100B includes a midsole 102 configured to provide cushioning characteristics to the sole structure 100A, 100B, and an outsole 104 configured to provide a ground-engaging surface 30 a of the article of footwear 10. Unlike conventional sole structures, the midsole 102 of the sole structure 100A, 100B may be formed compositely and include a plurality of subcomponents for providing desired forms of cushioning and support throughout the sole structure 100A, 100B. For example, the midsole 102 includes a cushion 106, and a chassis 108, where the chassis 108 is attached to the upper 300 and provides an interface between the upper 300A, 300B and the cushion 106.

With reference to FIGS. 1A-5B, a longitudinal axis A106 (shown in FIG. 5A-5B) of the cushion 106 extends from a first end 110 in the forefoot region 12 to a second end 112 in the heel region 16. The cushion 106 may be further described as including a top surface or side 114 and a bottom surface or side 116 formed on an opposite side of the cushion 106 from the top side 114. As discussed in greater detail below with respect to FIGS. 6A-8 , thicknesses T₁₀₆ of the cushion 106, or of elements of the cushion 106, are defined by a distance from the top side 114 to the bottom side 116.

The cushion 106 is configured to provide cushioning for the foot by attenuating ground-reaction forces. In one aspect, shown in FIGS. 5A and 6A, the cushion 106 is a fluid-filled bladder. As shown in the cross-sectional views of FIGS. 6A, 7 and 8 , the cushion 106 is a fluid-filled bladder that may be formed by an opposing pair of barrier layers 118, which can be joined to each other at discrete locations to define an overall shape of the cushion 106. Alternatively, the bladder 106 can be produced from any suitable combination of one or more barrier layers.

As used herein, the term “barrier layer” (e.g., barrier layers 118) encompasses both monolayer and multilayer films. In some configurations, one or both of the barrier layers 118 are each produced (e.g., thermoformed or blow molded) from a monolayer film (a single layer). In other configurations, one or both of the barrier layers 118 are each produced (e.g., thermoformed or blow molded) from a multilayer film (multiple sublayers). In either aspect, each layer or sublayer can have a film thickness ranging from about 0.2 micrometers to about 1 millimeter. In further configurations, the film thickness for each layer or sublayer can range from about 0.5 micrometers to about 500 micrometers. In yet further configurations, the film thickness for each layer or sublayer can range from about 1 micrometer to about 100 micrometers.

One or both of the barrier layers 118 can independently be transparent, translucent, and/or opaque. As used herein, the term “transparent” for a barrier layer and/or a bladder means that light passes through the barrier layer in substantially straight lines and a viewer can see through the barrier layer. In comparison, for an opaque barrier layer, light does not pass through the barrier layer and one cannot see clearly through the barrier layer at all. A translucent barrier layer falls between a transparent barrier layer and an opaque barrier layer, in that light passes through a translucent layer but some of the light is scattered so that a viewer cannot see clearly through the layer.

The barrier layers 118 can each be produced from an elastomeric material that includes one or more thermoplastic polymers and/or one or more cross-linkable polymers. In an aspect, the elastomeric material can include one or more thermoplastic elastomeric materials, such as one or more thermoplastic polyurethane (TPU) copolymers, one or more ethylene-vinyl alcohol (EVOH) copolymers, and the like.

As used herein, “polyurethane” refers to a copolymer (including oligomers) that contains a urethane group (—N(C═O)O—). These polyurethanes can contain additional groups such as ester, ether, urea, allophanate, biuret, carbodiimide, oxazolidinyl, isocynaurate, uretdione, carbonate, and the like, in addition to urethane groups. In an aspect, one or more of the polyurethanes can be produced by polymerizing one or more isocyanates with one or more polyols to produce copolymer chains having (—N(C═O)O—) linkages.

Examples of suitable isocyanates for producing the polyurethane copolymer chains include diisocyanates, such as aromatic diisocyanates, aliphatic diisocyanates, and combinations thereof. Examples of suitable aromatic diisocyanates include toluene diisocyanate (TDI), TDI adducts with trimethyloylpropane (TMP), methylene diphenyl diisocyanate (MDI), xylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), hydrogenated xylene diisocyanate (HXDI), naphthalene 1,5-diisocyanate (NDI), 1,5-tetrahydronaphthalene diisocyanate, para-phenylene diisocyanate (PPDI), 3,3′-dimethyldiphenyl-4,4′-diisocyanate (DDDI), 4,4′-dibenzyl diisocyanate (DBDI), 4-chloro-1,3-phenylene diisocyanate, and combinations thereof. In some configurations, the copolymer chains are substantially free of aromatic groups.

In particular aspects, the polyurethane polymer chains are produced from diisocynates including HMDI, TDI, MDI, H12 aliphatics, and combinations thereof. In an aspect, the thermoplastic TPU can include polyester-based TPU, polyether-based TPU, polycaprolactone-based TPU, polycarbonate-based TPU, polysiloxane-based TPU, or combinations thereof.

In another aspect, the polymeric layer can be formed of one or more of the following: EVOH copolymers, poly(vinyl chloride), polyvinylidene polymers and copolymers (e.g., polyvinylidene chloride), polyamides (e.g., amorphous polyamides), amide-based copolymers, acrylonitrile polymers (e.g., acrylonitrile-methyl acrylate copolymers), polyethylene terephthalate, polyether imides, polyacrylic imides, and other polymeric materials known to have relatively low gas transmission rates. Blends of these materials, as well as with the TPU copolymers described herein and optionally including combinations of polyimides and crystalline polymers, are also suitable.

The barrier layers 118 may include two or more sublayers (multilayer film) such as shown in Mitchell et al., U.S. Pat. No. 5,713,141 and Mitchell et al., U.S. Pat. No. 5,952,065, the disclosures of which are incorporated by reference in their entireties. In configurations where the barrier layers 118 include two or more sublayers, examples of suitable multilayer films include microlayer films, such as those disclosed in Bonk et al., U.S. Pat. No. 6,582,786, which is incorporated by reference in its entirety. In further configurations, the barrier layers 118 may each independently include alternating sublayers of one or more TPU copolymer materials and one or more EVOH copolymer materials, where the total number of sublayers in each of the barrier layers 118 includes at least four (4) sublayers, at least ten (10) sublayers, at least twenty (20) sublayers, at least forty (40) sublayers, and/or at least sixty (60) sublayers.

The cushion 106 can be produced from the barrier layers 118 using any suitable technique, such as thermoforming (e.g. vacuum thermoforming), blow molding, extrusion, injection molding, vacuum molding, rotary molding, transfer molding, pressure forming, heat sealing, casting, low-pressure casting, spin casting, reaction injection molding, radio frequency (RF) welding, and the like. In an aspect, the barrier layers 118 can be produced by co-extrusion followed by vacuum thermoforming to form the profile of the bladder 106, which can optionally include one or more valves (e.g., one way valves) that allow the bladder 106 to be filled with the fluid (e.g., gas).

The cushion 106 desirably has a low gas transmission rate to preserve its retained gas pressure. In some configurations, the bladder 106 has a gas transmission rate for nitrogen gas that is at least about ten (10) times lower than a nitrogen gas transmission rate for a butyl rubber layer of substantially the same dimensions. In an aspect, bladder 106 has a nitrogen gas transmission rate of 15 cubic-centimeter/square-meteratmosphereday (cm3/m2·atm·day) or less for an average film thickness of 500 micrometers (based on thicknesses of barrier layers 118). In further aspects, the transmission rate is 10 cm3/m2·atm·day or less, 5 cm3/m2·atm·day or less, or 1 cm3/m2·atm·day or less.

In the shown configuration, the barrier layers 118 include a first, upper barrier layer 118 forming the top side 114 of the cushion 106, and a second, lower barrier layer 118 forming the bottom side 116 of the cushion 106. In the illustrated example, interior, opposing surfaces (i.e. facing each other) of the barrier layers 118 are joined together at discrete locations to form a weld 120 and a peripheral seam 122 and are spaced apart from each other to form a void 124, which may be pressurized with a fluid or a gas. The peripheral seam 122 extends around the outer periphery of the cushion 106 and defines an outer peripheral profile of the cushion 106. As shown in FIGS. 6A-8 , the upper and lower barrier layers 118 are spaced apart from each other between the weld 120 and the peripheral seam 122 to define a peripheral chamber 126 and an inner chamber 128. The inner chamber 128 of the first article of footwear 10A is disposed on the lateral side 24 and the inner chamber 128 of the second article of footwear 10B is disposed on the medial side 22. Further, the peripheral chamber 126 of the first article of footwear 10A is disposed on the medial side 22 and the peripheral chamber 126 of the second article of footwear 10B is disposed on the lateral side 24.

With reference now to FIGS. 5B and 6B, another aspect of the cushion 106 is provided wherein the cushion 106 includes a tensile element 130A, 130B disposed within the void 124 of the respective peripheral chamber 126 and the inner chamber 128. When filled with a pressurized fluid, the peripheral chamber 126 and the inner chamber 128 expand and the tensile element 130A-130B is placed in tension. While these elements 130A-130B are placed in tension, a desired shape of each chamber 126, 128 is maintained due to the relationship between the tensile element 130A-130B and the respective chamber 126, 128.

Each tensile element 130A, 130B may include a series of tensile strands 132 extending between upper and lower tensile layers 134A, 134B. The upper tensile layer 134A may be attached to the upper barrier layer 118 while the lower tensile layer 134B may be attached to the lower barrier layer 118. In this manner, when each of the respective peripheral chamber 126 and the inner chamber 128 receives a pressurized fluid, the tensile strands 132 of the tensile elements 130A-130B are placed in tension. Because the upper tensile layer 134A is attached to the upper barrier layer 118 and the lower tensile layer 134B is attached to the lower barrier layer 118, the tensile strands 132 retain a desired shape of each of the peripheral chamber 126 and the inner chamber 128 when the pressurized fluid is injected into the void 124.

As shown in FIGS. 2A-3B, the cushion 106 of the first article of footwear 10A is identical to the cushion 106 of the second article of footwear 10B. Accordingly, a discussion of the cushion 106 of the first article of footwear 10A is applicable to the cushion of the second article of footwear 10B. The peripheral chamber 126 extends from the heel region 15 to the forefoot region 12 and widens around the midfoot region 14 to the forefoot region 12, as shown in FIGS. 5A, 5B. In particular, the peripheral chamber 126 of the cushion 106 for use in the first article of footwear 10A extends continuously and uninterrupted from a forefoot region 12 of the first sole structure 100A to a heel region 16 of the first sole structure 100A along the medial side 22. Likewise, the peripheral chamber 126 of the cushion 106 for use in the second article of footwear 10B extends continuously and uninterrupted from a forefoot region 12 of the second sole structure 100B to a heel region 16 of the second sole structure 100B along the lateral side 22. The widest portion of the cushion 106 is located generally at the center of the forefoot region 12, with respect to a length of the cushion 106, and tapers to a flattened end at the most forward end of the cushion 106.

The weld 120 is generally U-shaped with each end joined to the peripheral seam 122 in a seamless and contiguous manner. The weld 120 has a generally constant width, as shown in FIGS. 2A-3B and 7 . The inner chamber 128 is disposed at the forefoot region 12. The weld 120 of the cushion 106 for use in the first article of footwear 10A extends from a first lateral edge 120A1 located on the lateral side 24 in a direction towards the medial side 22 and continues from the medial side 22 to a second lateral edge 120A2 located on the lateral side 24, wherein the first lateral edge 120A1 is spaced apart from the second lateral edge 120A2. Likewise, the weld 120 of the cushion 106 for use in the second article of footwear 10B extends from a first medial edge 120B1 located on the medial side 22 in a direction towards the lateral side 24 and continues from the medial side 22 to a second medial edge 120B2 located on the medial side 22, wherein the first medial edge 120B1 is spaced apart from the second medial edge 120B2.

With reference now to FIGS. 6A and 6B, the thicknesses T₁₀₆ of the cushion 106 is substantially constant from an anterior end to the posterior end of the cushion 106 as well as along the width of the cushion. The profile of the cushion 106, as taken along the length of the cushion 106, includes a curvature along the midfoot region 14 to the forefoot region 12 so as to accommodate the arch of a foot. The cushion 106 is wider at the anterior end relative to the posterior end of the heel region 16 as shown in FIG. 8 . The cushion 106 begins to widen at the midfoot region 16 so as to define a generally pear-shaped structure.

With continued reference to FIGS. 2A and 2B, the chassis 108 is configured to interface with the cushion 106. The chassis 108 extends from a first end 136 at the anterior end 18 of the sole structure 100A, 100B to a second end 138 at the posterior end 20 of the sole structure 100. The chassis 108 further includes a top surface 140 defining a portion of a footbed, and a bottom surface 142 formed on the opposite side of the chassis 108 than the top surface 140 and configured to interface with the top side 114 of the cushion 106.

The chassis 108 may be formed as a unitary piece, or may be formed of a plurality of elements as discussed in greater detail below. The chassis 108, like the cushion 106, has a generally pear-shaped construction and is preferably wider than the cushion 106. In one aspect, the chassis 108 includes an upper insert 144 and a lower insert 146. Both the upper insert 144 and the lower insert include a first end 136 that is generally flat and extends along an axis from the medial side 22 to the lateral side 24 of the chassis 108. The upper insert 144 and the lower insert 146 are dimensioned the same as each other and extend the length of the sole structure 100 a, 100 b. The upper insert 144 and the lower insert 146 may be fixed together using an adhesive, vibrational welding, heat fusing or the like. In another aspect, the upper insert 144 and the lower insert 146 are formed as a unitary piece.

The chassis 108 may further include a heel support 148 configured to secure the anterior end of the cushion 106 with respect to the outsole 104 and the lower and upper inserts 144, 146. The heel support 148 is generally U-shaped and includes a planar bottom surface (shown in FIGS. 3A, 3B) configured to be secured to a midsole-engaging surface 30 b of the outsole 104. The midsole-engaging surface 30 b is opposite of a ground-engaging surface 30. The inner surface of the heel support 148 includes a peripheral slot 150 that is continuous so as to define a generally U-shaped structure. The peripheral slot 150 is configured to receive a corresponding portion of the peripheral seam 122 of the cushion. Preferably, the peripheral seam 122 is secured to the peripheral slot 150 using an adhesive, vibrational welding, heat fusing or the like. The heel support 148 may further include an upper ledge 152 disposed on the inner surface of the heel support 148. The upper ledge 152 is continuous from one end of the heel support 148 to the other. The upper ledge 152 is a generally planar surface configured to receive the bottom surface of the lower insert 146. The heel support 148 may further include a heel projection 154 disposed on a top surface of the heel support 148 and at the posterior end of the heel support 148. The heel projection 154 is configured to cup the rearward portion of a user's heel.

With continued reference to FIGS. 2A-3B, the chassis 108 may further include a toe support 158 including a support portion 158 configured to abut against the anterior end of the cushion 106. An anterior end of the support portion 158 is rounded so as to facilitate a heel-to-toe strike of the first and second article of footwear 10A, 10B. Namely, the cushion 106 has a length that is shorter than a length of upper insert 144 and lower insert 146 so as to define an axial gap 162 (shown in FIG. 12 ) from the first end 110 of the cushion 106 and the first end 136 of the upper and lower inserts 144, 146.

The support portion 158 of the toe support 158 occupies the axial gap 162 so as to provide support for the toes of the user. The anterior end of the support portion 158 remains spaced apart from the anterior end of the cushion 106 so as to allow the toe support 158 to flex freely relative to the cushion 106, as shown in FIG. 12 . The toe support 158 includes a recessed surface 160, which is recessed with respect to an upper surface of the toe support 158 disposed at the anterior end of the toe support 158. The toe support 158 further includes a back wall 164 defining the posterior end of the toe support 158. The recessed surface 160 is recessed so as to accommodate the upper insert 144 and the lower insert 146 and position the top surface of the upper insert 144 to be contiguous with the top surface of the toe support 158.

With reference now to FIGS. 9 and 10 , the kit 400 further includes a side support 166. As shown in FIGS. 2A-3B, the side support 166 is configured to provide support for the outer side of the first article of footwear 10A and the second article of footwear 10B with respect to a counter clockwise direction of a track so as to provide support while the user is rounding a turn. In particular, the side support or first side support 166 a is attached to the medial side 22 of the first article of footwear 10A and the side support or second side support 166 b is attached to the lateral side 24 of the second article of footwear 10B. FIG. 2A shows the first side support 166 a is identical to the second side support 166 b and, thus, a description of the side support 166 shown in FIGS. 9 and 10 is sufficient to describe the first side support 166 a shown in FIGS. 2A and 3A and the second side support 166 b shown in FIGS. 2B and 3B. As shown in FIGS. 1A and 1B, the side support 166 a, 166 b may be fixed to the outsole 104, the cushion 106, and the upper 300A using an adhesive to secure the outsole, the cushion 106, and the upper 300A together. Preferably, the side support 166 a, 166 b is formed of a material having a higher rigidity than a material forming the cushion 106.

The side support 166 includes a side wall 168 having a generally convex outer surface. The side wall 168 includes a plurality of gaps 168 a spaced apart from each other so as to define a plurality of slats 168 b spaced apart from each other. The side support 166 further includes a base member 170 and a brace 172. The base member 170 is disposed on a bottom portion of inner surface of the side wall 168 and includes a bottom surface configured to be fixed to the midsole-engaging surface 30 b of the outsole 104. The base member 170 may be fixed to the midsole-engaging surface 30 b of the outsole 104 by an adhesive, vibrational welding, heat fusion or the like. The brace 172 is disposed on an upper portion side wall 168 and fixes the slats 168 b with respect to each other. The brace 172 includes a wedge portion 174, which is configured to occupy a space between the bottom surface of the lower insert 146 and the top surface 114 of the cushion 106. Each of the slats 168 b includes a slit 176 having a height configured to fittingly receive a thickness of the peripheral seam 122 of the cushion 106 so as to help secure the side support 166 to the cushion 106, as shown in FIGS. 1A and 1B.

With reference now to FIG. 11 , a top down view of the first article of footwear 10A is provided. The sole structure 100A is configured to provide support for the user's foot as the user rounds a turn on a track in a counter-clockwise direction. The side support 166, or more particularly, the first side support 166 a is disposed on the medial side 22. FIG. 13 illustrates the engagement of the toe support 158 with respect to the outsole 104 and the upper insert 144 and the lower insert 146. In particular, the toe support 158 is flush against the midsole-engaging surface 30 b, and the upper insert 144 and the lower insert 146 are flush against each other, and the lower insert 146 is flush against the recessed surface 160 of the toe support portion 158.

FIG. 14 is a cross-sectional view of the sole structure 100 a of the first article of footwear 10A and the outsole 104 taken along the forefoot region. FIG. 14 depicts the peripheral chamber 126 being located along the medial side 22 of the sole structure 100 a, wherein the peripheral chamber 126 is wider than the inner chamber 128. Accordingly, more support and structure is provided along the medial side 22 of the sole structure 100 a relative to the lateral side 24 so as to provide support to the medial side of the user's left foot when rounding a turn on a track in a counter-clockwise direction. Likewise, the peripheral chamber 126 of sole structure 100 b of the second article of footwear 10B is located along the lateral side 24 and is wider than the inner chamber 128 so as to provide more support and structure along the lateral side 24. Accordingly, the lateral side 24 is configured to support the lateral side of the user's right foot when rounding a turn on a track in a counter-clockwise direction.

FIGS. 15 and 16 show how the cushion 106 widens from the mid-foot region 14 towards the heel region 16. FIG. 17 shows the cushion 106 received within the heel support 148. In particular, the peripheral seam 122 is fixed to the peripheral slot 150 of the heel support 148. The top surface of the upper insert 144 is seamless with a top surface of the heel support 148.

Example resilient polymeric materials for the chassis may include those based on foaming or molding one or more polymers, such as one or more elastomers (e.g., thermoplastic elastomers (TPE)). The one or more polymers may include aliphatic polymers, aromatic polymers, or mixtures of both; and may include homopolymers, copolymers (including terpolymers), or mixtures of both.

In some aspects, the one or more polymers may include olefinic homopolymers, olefinic copolymers, or blends thereof. Examples of olefinic polymers include polyethylene, polypropylene, and combinations thereof. In other aspects, the one or more polymers may include one or more ethylene copolymers, such as, ethylene-vinyl acetate (EVA) copolymers, EVOH copolymers, ethylene-ethyl acrylate copolymers, ethylene-unsaturated mono-fatty acid copolymers, and combinations thereof.

In further aspects, the one or more polymers may include one or more polyacrylates, such as polyacrylic acid, esters of polyacrylic acid, polyacrylonitrile, polyacrylic acetate, polymethyl acrylate, polyethyl acrylate, polybutyl acrylate, polymethyl methacrylate, and polyvinyl acetate; including derivatives thereof, copolymers thereof, and any combinations thereof.

In yet further aspects, the one or more polymers may include one or more ionomeric polymers. In these aspects, the ionomeric polymers may include polymers with carboxylic acid functional groups, sulfonic acid functional groups, salts thereof (e.g., sodium, magnesium, potassium, etc.), and/or anhydrides thereof. For instance, the ionomeric polymer(s) may include one or more fatty acid-modified ionomeric polymers, polystyrene sulfonate, ethylene-methacrylic acid copolymers, and combinations thereof.

In further aspects, the one or more polymers may include one or more styrenic block copolymers, such as acrylonitrile butadiene styrene block copolymers, styrene acrylonitrile block copolymers, styrene ethylene butylene styrene block copolymers, styrene ethylene butadiene styrene block copolymers, styrene ethylene propylene styrene block copolymers, styrene butadiene styrene block copolymers, and combinations thereof.

In further aspects, the one or more polymers may include one or more polyamide copolymers (e.g., polyamide-polyether copolymers) and/or one or more polyurethanes (e.g., crosslinked polyurethanes and/or thermoplastic polyurethanes). Examples of suitable polyurethanes include those discussed above for barrier layers 118. Alternatively, the one or more polymers may include one or more natural and/or synthetic rubbers, such as butadiene and isoprene.

When the resilient polymeric material is a foamed polymeric material, the foamed material may be foamed using a physical blowing agent which phase transitions to a gas based on a change in temperature and/or pressure, or a chemical blowing agent which forms a gas when heated above its activation temperature. For example, the chemical blowing agent may be an azo compound such as adodicarbonamide, sodium bicarbonate, and/or an isocyanate.

In some configurations, the foamed polymeric material may be a crosslinked foamed material. In these configurations, a peroxide-based crosslinking agent such as dicumyl peroxide may be used. Furthermore, the foamed polymeric material may include one or more fillers such as pigments, modified or natural clays, modified or unmodified synthetic clays, talc glass fiber, powdered glass, modified or natural silica, calcium carbonate, mica, paper, wood chips, and the like.

The resilient polymeric material may be formed using a molding process. In one example, when the resilient polymeric material is a molded elastomer, the uncured elastomer (e.g., rubber) may be mixed in a Banbury mixer with an optional filler and a curing package such as a sulfur-based or peroxide-based curing package, calendared, formed into shape, placed in a mold, and vulcanized.

In another example, when the resilient polymeric material is a foamed material, the material may be foamed during a molding process, such as an injection molding process. A thermoplastic polymeric material may be melted in the barrel of an injection molding system and combined with a physical or chemical blowing agent and optionally a crosslinking agent, and then injected into a mold under conditions which activate the blowing agent, forming a molded foam.

Optionally, when the resilient polymeric material is a foamed material, the foamed material may be a compression molded foam. Compression molding may be used to alter the physical properties (e.g., density, stiffness and/or durometer) of a foam, or to alter the physical appearance of the foam (e.g., to fuse two or more pieces of foam, to shape the foam, etc.), or both.

The compression molding process desirably starts by forming one or more foam preforms, such as by injection molding and foaming a polymeric material, by forming foamed particles or beads, by cutting foamed sheet stock, and the like. The compression molded foam may then be made by placing the one or more preforms formed of foamed polymeric material(s) in a compression mold, and applying sufficient pressure to the one or more preforms to compress the one or more preforms in a closed mold. Once the mold is closed, sufficient heat and/or pressure is applied to the one or more preforms in the closed mold for a sufficient duration of time to alter the preform(s) by forming a skin on the outer surface of the compression molded foam, fuse individual foam particles to each other, permanently increase the density of the foam(s), or any combination thereof. Following the heating and/or application of pressure, the mold is opened and the molded foam article is removed from the mold.

In some examples, the outsole 104 is a first plate and extends over the midsole 102 to provide increased durability and resiliency. In the illustrated example, the outsole 104 is provided as a polymeric layer that is overmolded onto portions of the bottom side 116 of the cushion 106 to provide increased durability to the exposed portions of the lower barrier layer 118 of the cushion 106. Accordingly, the outsole 104 is formed of a different material than the cushion 106, and includes at least one of a different thickness, a different hardness, and a different abrasion resistance than the lower barrier layer 118. In some examples, the outsole 104 may be formed integrally with the lower barrier layer 118 of the cushion 106 using an overmolding process. In other examples, the outsole 104 may be formed separately from the lower barrier layer 118 of the cushion 106 and may be adhesively bonded to the lower barrier layer 118.

With reference again to FIGS. 2A-3B, the outsole 104 is a plate and is attached to the bottom side of the cushion 106, and spaced apart from the weld 120. An anterior end of the outsole 104 is attached to the heel support 148. In particular, the midsole-engaging surface 30 b is attached to a bottom surface of the heel support 148. The medial side 22 of the outsole 104 of the first article of footwear 10A includes a first recess 178 a configured to accommodate the base member 170 of side support 166 a. The lateral side 24 of the outsole 104 of the second article of footwear 10B includes a second recess 178 b configured to accommodate the base member 170 of side support 166 b. Within the forefoot region 12, the outsole 104 includes a plurality of holes 180 configured to receive a corresponding number of spikes 182. In one aspect, the holes 180 are threaded and the spikes have a threaded stud configured to threadedly engage the corresponding holes 180. The holes 180 are generally flush with the midsole-engaging surface 30 b and are generally frustoconical on the ground-engaging surface 30 a of the outsole 104.

The upper 300 is attached to the sole structure 100 and includes interior surfaces that define an interior void configured to receive and secure a foot for support on sole structure 100. The upper 300 may be formed from one or more materials that are stitched or adhesively bonded together to form the interior void. Suitable materials of the upper 300 may include, but are not limited to, mesh, textiles, foam, leather, and synthetic leather. The materials may be selected and located to impart properties of durability, air-permeability, wear-resistance, flexibility, and comfort.

The following Clauses provide exemplary configurations for an article of footwear and a kit having a pair of articles of footwear described above.

Clause 1. A kit including a first article of footwear and a second article of footwear, wherein the first article of footwear includes a first upper, a first sole structure having a first outsole defining a first ground-contacting surface, and a first side support extending between and connecting the first upper and the first outsole at a medial side of the first article of footwear; and the second article of footwear including a second upper, a second sole structure having a second outsole defining a second ground-contacting surface, and a second side support extending between and connecting the second upper and the second outsole at a lateral side of the second article of footwear.

Clause 2. The kit of Clause 1, wherein the first outsole is a first plate and the second outsole is a second plate.

Clause 3. The kit of Clause 2, further including a first fluid-filled chamber disposed between the first plate and the first upper and a second fluid-filled chamber disposed between the second plate and the second upper.

Clause 4. The kit of Clause 3, wherein the first plate and the first side support include a higher rigidity than a material forming the first fluid-filled chamber and the second plate and the second side support include a higher rigidity than a material forming the second fluid-filled chamber.

Clause 5. The kit of Clause 1, wherein the first side support is disposed in a forefoot region of the first sole structure and the second side support is disposed in a forefoot region of the second sole structure.

Clause 6. The kit of Clause 1, wherein the first sole structure includes a first fluid-filled chamber disposed between the first outsole and the first upper and the second sole structure includes a second fluid-filled chamber disposed between the second outsole and the second upper.

Clause 7. The kit of Clause 6, wherein at least one of the first fluid-filled chamber and the second fluid-filled chamber is pressurized and/or includes a tensile member disposed therein.

Clause 8. The kit of Clause 6, wherein the first fluid-filled chamber extends continuously and uninterrupted from a forefoot region of the first sole structure to a heel region of the first sole structure along the medial side and the second fluid-filled chamber extends continuously and uninterrupted from a forefoot region of the second sole structure to a heel region of the second sole structure along the lateral side.

Clause 9. The kit of Clause 8, wherein the first fluid-filled chamber includes at least one first weld extending from a lateral edge of the first fluid-filled chamber in a direction toward the medial side of the first sole structure and the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.

Clause 10. The kit of Clause 9, wherein the first fluid-filled chamber and the second fluid-filled chamber are identical to one another.

Clause 11. A kit comprising a first article of footwear and a second article of footwear, the first article of footwear including: (i) a first upper; and (ii) a first sole structure having a first plate defining a first ground-contacting surface and a first fluid-filled chamber disposed between the first plate and the first upper, the first fluid-filled chamber extending continuously and uninterrupted from a forefoot region of the first sole structure to a heel region of the first sole structure along a medial side of the first sole structure; and the second article of footwear including (i) a second upper; and (ii) a second sole structure having a second plate defining a second ground-contacting surface and a second fluid-filled chamber disposed between the second plate and the second upper, the second fluid-filled chamber extending continuously and uninterrupted from a forefoot region of the second sole structure to a heel region of the second sole structure along a lateral side of the second sole structure.

Clause 12. The kit of Clause 11, wherein the first fluid-filled chamber includes at least one first weld extending from a lateral edge of the first fluid-filled chamber in a direction toward the medial side of the first sole structure.

Clause 13. The kit of Clause 12, wherein the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.

Clause 14. The kit of Clause 11, wherein the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.

Clause 15. The kit of Clause 11, wherein at least one of the first fluid-filled chamber and the second fluid-filled chamber is pressurized and/or includes a tensile member disposed therein.

Clause 16. The kit of Clause 11, wherein the first fluid-filled chamber and the second fluid-filled chamber are identical to one another.

Clause 17. The kit of Clause 11, further comprising a first side support extending between and connecting the first upper and the first plate at a medial side of the first article of footwear and a second side support extending between and connecting the second upper and the second plate at a lateral side of the second article of footwear.

Clause 18. The kit of Clause 17, wherein the first plate and the first side support include a higher rigidity than a material forming the first fluid-filled chamber and the second plate and the second side support include a higher rigidity than a material forming the second fluid-filled chamber.

Clause 19. The kit of Clause 17, wherein the first side support is disposed in a forefoot region of the first sole structure and the second side support is disposed in a forefoot region of the second sole structure.

Clause 20. The kit of Clause 17, wherein the first side support and the second side support include a plurality of gaps spaced apart from each other to define a plurality of slats.

The foregoing description has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but, where applicable, are interchangeable and can be used in a selected configuration, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure. 

What is claimed is:
 1. A kit comprising: a first article of footwear including a first upper, a first sole structure having a first outsole defining a first ground-contacting surface, and a first side support extending between and connecting the first upper and the first outsole at a medial side of the first article of footwear; and a second article of footwear including a second upper, a second sole structure having a second outsole defining a second ground-contacting surface, and a second side support extending between and connecting the second upper and the second outsole at a lateral side of the second article of footwear.
 2. The kit of claim 1, wherein the first outsole is a first plate and the second outsole is a second plate.
 3. The kit of claim 2, further comprising a first fluid-filled chamber disposed between the first plate and the first upper and a second fluid-filled chamber disposed between the second plate and the second upper.
 4. The kit of claim 3, wherein the first plate and the first side support include a higher rigidity than a material forming the first fluid-filled chamber and the second plate and the second side support include a higher rigidity than a material forming the second fluid-filled chamber.
 5. The kit of claim 1, wherein the first side support is disposed in a forefoot region of the first sole structure and the second side support is disposed in a forefoot region of the second sole structure.
 6. The kit of claim 1, wherein the first sole structure includes a first fluid-filled chamber disposed between the first outsole and the first upper and the second sole structure includes a second fluid-filled chamber disposed between the second outsole and the second upper.
 7. The kit of claim 6, wherein at least one of the first fluid-filled chamber and the second fluid-filled chamber is pressurized and/or includes a tensile member disposed therein.
 8. The kit of claim 6, wherein the first fluid-filled chamber extends continuously and uninterrupted from a forefoot region of the first sole structure to a heel region of the first sole structure along the medial side and the second fluid-filled chamber extends continuously and uninterrupted from a forefoot region of the second sole structure to a heel region of the second sole structure along the lateral side.
 9. The kit of claim 8, wherein the first fluid-filled chamber includes at least one first weld extending from a lateral edge of the first fluid-filled chamber in a direction toward the medial side of the first sole structure and the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.
 10. The kit of claim 9, wherein the first fluid-filled chamber and the second fluid-filled chamber are identical to one another.
 11. A kit comprising: a first article of footwear including (i) a first upper and (ii) a first sole structure having a first plate defining a first ground-contacting surface and a first fluid-filled chamber disposed between the first plate and the first upper, the first fluid-filled chamber extending continuously and uninterrupted from a forefoot region of the first sole structure to a heel region of the first sole structure along a medial side of the first sole structure; and a second article of footwear including (i) a second upper and (ii) a second sole structure having a second plate defining a second ground-contacting surface and a second fluid-filled chamber disposed between the second plate and the second upper, the second fluid-filled chamber extending continuously and uninterrupted from a forefoot region of the second sole structure to a heel region of the second sole structure along a lateral side of the second sole structure.
 12. The kit of claim 11, wherein the first fluid-filled chamber includes at least one first weld extending from a lateral edge of the first fluid-filled chamber in a direction toward the medial side of the first sole structure.
 13. The kit of claim 12, wherein the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.
 14. The kit of claim 11, wherein the second fluid-filled chamber includes at least one second weld extending from a medial edge of the second fluid-filled chamber in a direction toward the lateral side of the second sole structure.
 15. The kit of claim 11, wherein at least one of the first fluid-filled chamber and the second fluid-filled chamber is pressurized and/or includes a tensile member disposed therein.
 16. The kit of claim 11, wherein the first fluid-filled chamber and the second fluid-filled chamber are identical to one another.
 17. The kit of claim 11, further comprising a first side support extending between and connecting the first upper and the first plate at a medial side of the first article of footwear and a second side support extending between and connecting the second upper and the second plate at a lateral side of the second article of footwear.
 18. The kit of claim 17, wherein the first plate and the first side support include a higher rigidity than a material forming the first fluid-filled chamber and the second plate and the second side support include a higher rigidity than a material forming the second fluid-filled chamber.
 19. The kit of claim 17, wherein the first side support is disposed in a forefoot region of the first sole structure and the second side support is disposed in a forefoot region of the second sole structure.
 20. The kit of claim 17, wherein the first side support and the second side support include a plurality of gaps spaced apart from each other to define a plurality of slats. 